diff --git a/neptyne_kernel/json_tools.py b/neptyne_kernel/json_tools.py
index c76fc37..20d9644 100644
--- a/neptyne_kernel/json_tools.py
+++ b/neptyne_kernel/json_tools.py
@@ -21,6 +21,9 @@ def json_default(obj: Any) -> str | int | list | float | None:
     except ImportError:
         from jupyter_client.jsonutil import date_default as jupyter_json_default
 
+    if hasattr(obj, "__json__"):
+        obj = obj.__json__()
+
     return jupyter_json_default(obj)
 
 
diff --git a/neptyne_kernel/requirements-extras.in b/neptyne_kernel/requirements-extras.in
index b43a9c2..26adb74 100644
--- a/neptyne_kernel/requirements-extras.in
+++ b/neptyne_kernel/requirements-extras.in
@@ -15,7 +15,6 @@ graphlib
 html5lib
 isoweek
 jaconv
-json-fix
 mapboxgl
 mapclassify
 markdown
diff --git a/neptyne_kernel/requirements.txt b/neptyne_kernel/requirements.txt
index 43a72ec..927c1c7 100644
--- a/neptyne_kernel/requirements.txt
+++ b/neptyne_kernel/requirements.txt
@@ -278,8 +278,6 @@ joblib==1.3.2
     # via
     #   contextily
     #   scikit-learn
-json-fix==0.3.0
-    # via -r neptyne_kernel/requirements-extras.in
 jsonschema==4.5.1
     # via
     #   altair
diff --git a/neptyne_kernel/widgets/base_widget.py b/neptyne_kernel/widgets/base_widget.py
index 5de8e55..5682289 100644
--- a/neptyne_kernel/widgets/base_widget.py
+++ b/neptyne_kernel/widgets/base_widget.py
@@ -11,11 +11,6 @@
 from enum import Enum
 from typing import Any, Callable
 
-try:
-    import json_fix  # pylint: disable=unused-import # noqa: F401
-except ImportError:
-    pass
-
 from ..cell_api import CellApiMixin, CellEvent
 from ..neptyne_protocol import MIMETypes
 from ..util import list_like
diff --git a/requirements-dev.txt b/requirements-dev.txt
index a08dbdc..7c371f4 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -441,8 +441,6 @@ joblib==1.3.2
     #   -r requirements.txt
     #   contextily
     #   scikit-learn
-json-fix==0.3.0
-    # via -r neptyne_kernel/requirements-extras.in
 jsonschema==4.5.1
     # via
     #   -r requirements.txt
diff --git a/requirements.in b/requirements.in
index 62c8dc5..c124d28 100644
--- a/requirements.in
+++ b/requirements.in
@@ -39,7 +39,6 @@ ipython~=8.3.0
 isort
 isoweek
 jaconv
-json-fix
 jupyter_client
 kaleido
 kubernetes_asyncio
diff --git a/requirements.txt b/requirements.txt
index 15e31f7..544f372 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -323,8 +323,6 @@ jiter==0.5.0
     # via anthropic
 joblib==1.3.2
     # via scikit-learn
-json-fix==1.0.0
-    # via -r requirements.in
 jsonschema==4.5.1
     # via
     #   altair